Q 01/05

How many lobes does the right human lung have?

A) Two

B) Three

C) Four

D) Five

Answer · why

B) Three

The left lung has only two lobes, because it gives up room to the heart and has a cardiac notch instead of a middle lobe.

Q 02/05

Which muscle is described as the most important muscle of respiration?

A) The pectoralis major

B) The rectus abdominis

C) The diaphragm

D) The trapezius

Answer · why

C) The diaphragm

When it contracts the chest cavity gets bigger, pressure drops, and air is pulled in; relaxing it pushes the air back out.

Q 03/05

What is the common name for the trachea?

A) The gullet

B) The voice box

C) The windpipe

D) The breastbone

Answer · why

C) The windpipe

It links the larynx to the bronchi and is found in almost every land vertebrate with lungs.

Q 04/05

Roughly how many rings of hyaline cartilage surround the adult trachea?

A) 16 to 20

B) 25 to 30

C) 40 to 45

D) 60 to 70

Answer · why

A) 16 to 20

The rings are incomplete and C-shaped, with the open side at the back so the oesophagus behind it can bulge when you swallow.

Q 05/05

What shape are the cartilage hoops of the trachea?

A) Complete and O-shaped

B) Incomplete and C-shaped

C) Spiral coils

D) Flat square plates

Answer · why

B) Incomplete and C-shaped

Complete O rings do occur as a rare abnormality and can narrow the airway enough to cause breathing trouble.